Pallas's Grasshopper Warbler

Pallas's grasshopper warbler, also called the rusty-rumped warbler, is a medium-sized warbler. The adult has a streaked brown back and whitish-grey underparts, unstreaked except on the undertail. The sexes are identical, and young birds are yellower below. It is very similar to the common grasshopper warbler but slightly larger, with white tips to the tail and tertial feathers and a warmer brown rump; the white tips give it the mnemonic name PG Tips. It is a skulking species, hard to see except sometimes when singing, creeping through grass and low foliage. (Wikipedia, general species account)

It breeds in the eastern Palearctic, from the Altai Mountains, Mongolia and Transbaikalia to northeastern China, the Korean Peninsula and islands in the Sea of Okhotsk, and winters from India east to Indonesia. It lives in tall grass with some thicker vegetation, usually close to water in bogs or wet meadows, laying four to seven eggs in a nest on the ground in grass. It is a very rare vagrant to western Europe, with Fair Isle in Shetland one of the best places to see it. (Wikipedia, general species account)